In EP0735847 is described an orthosis for the treatment of scoliotic deformities in children, and comprising basically an upper thoracic attachment means and a lower pelvic, attachment means with semi-elastic means adapted to be anchored at upper and lower parts thereof respectively to said upper and lower attachment means and to extend substantially obliquely intermediate said upper and lower attachment means. The function of the semi-elastic means is to exert derotational forces on the thoracic and lumber spines of the user in opposite directions. Whilst this orthosis has been used successfully for a number of years its design, as indicated above, was for children, where correction of a problem was an objective although fitting results in a mobility problem for the user.